golang基礎-模板渲染（終端、瀏覽器）、渲染輸出檔案、自定義io.Writer渲染
阿新 • • 發佈：2019-01-02
模板渲染終端
1）替換 {{.欄位名}}
demo.go
package main
import (
"fmt"
"os"
"text/template"
)
type Person struct {
Name string
age string
}
func main() {
t, err := template.ParseFiles("e:/golang/go_pro/src/safly/index.html")
if err != nil {
fmt.Println("parse file err:", err)
return
}
p := Person{Name: "Mary" index.html
<html>
<head>
<title>
</title>
</head>
<body>
<p>
<!--p代表當前物件-->
hello,{{.Name}}{{. 然後在終端就可以渲染輸出如下：
PS E:\golang\go_pro\src\safly> go run demo.go
<html>
<head>
<title>
</title>
</head>
<body>
<p>
<!--p代表當前物件-->
hello,Mary
{Mary 31}
</p>
</body 模板渲染瀏覽器輸出
index.html保持不變
package main
import (
"fmt"
"html/template"
// "io"
"net/http"
)
var myTemplate *template.Template
type Person struct {
Name string
age string
}
func userInfo(w http.ResponseWriter,r *http.Request) {
p := Person{Name:"safly",age:"30"}
myTemplate.Execute(w,p)
}
func initTemplate(fileName string) (err error){
myTemplate,err = template.ParseFiles(fileName)
if err != nil{
fmt.Println("parse file err:",err)
return
}
return
}
/*
func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
DefaultServeMux.HandleFunc(pattern, handler)
}
*/
func main() {
initTemplate("e:/golang/go_pro/src/safly/index.html")
http.HandleFunc("/user/info", userInfo)
err := http.ListenAndServe("0.0.0.0:8880", nil)
if err != nil {
fmt.Println("http listen failed")
}
}
模板渲染儲存檔案
package main
import (
"os"
"fmt"
"html/template"
// "io"
"net/http"
)
var myTemplate *template.Template
type Person struct {
Name string
age string
}
func userInfo(w http.ResponseWriter,r *http.Request) {
p := Person{Name:"safly",age:"30"}
myTemplate.Execute(os.Stdout,p)
file,err := os.OpenFile("demo.dat", os.O_CREATE|os.O_WRONLY, 0755)
if err != nil {
fmt.Println("open failed err:", err)
return
}
myTemplate.Execute(file,p)
}
func initTemplate(fileName string) (err error){
myTemplate,err = template.ParseFiles(fileName)
if err != nil{
fmt.Println("parse file err:",err)
return
}
return
}
/*
func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
DefaultServeMux.HandleFunc(pattern, handler)
}
*/
func main() {
initTemplate("e:/golang/go_pro/src/safly/index.html")
http.HandleFunc("/user/info", userInfo)
err := http.ListenAndServe("0.0.0.0:8880", nil)
if err != nil {
fmt.Println("http listen failed")
}
}
然後demo.dat就被渲染輸出內容了：
自定義io.Writer渲染
我們看下myTemplate.Execute原始碼
func (t *Template) Execute(wr io.Writer, data interface{}) error {
if err := t.escape(); err != nil {
return err
}
return t.text.Execute(wr, data)
}type Writer interface {
Write(p []byte) (n int, err error)
}所以我們實現Writer介面方法Write就可以自定義了
package main
import (
// "os"
"fmt"
"html/template"
"io"
"net/http"
)
var myTemplate *template.Template
type Person struct {
Name string
age string
}
type Result struct {
output string
}
/*
自定義實現介面
type Writer interface {
Write(p []byte) (n int, err error)
}
*/
func (p *Result) Write(b []byte) (n int, err error) {
fmt.Println("called by template")
p.output += string(b)
return len(b), nil
}
/*
func WriteString(w Writer, s string) (n int, err error) {
if sw, ok := w.(stringWriter); ok {
return sw.WriteString(s)
}
return w.Write([]byte(s))
}
*/
func userInfo(w http.ResponseWriter,r *http.Request) {
p := Person{Name:"safly",age:"30"}
resultWriter := &Result{}
io.WriteString(resultWriter, "hello world")
myTemplate.Execute(resultWriter,p)
fmt.Println("render data:",resultWriter.output)
}
func initTemplate(fileName string) (err error){
myTemplate,err = template.ParseFiles(fileName)
if err != nil{
fmt.Println("parse file err:",err)
return
}
return
}
/*
func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
DefaultServeMux.HandleFunc(pattern, handler)
}
*/
func main() {
initTemplate("e:/golang/go_pro/src/safly/index.html")
http.HandleFunc("/user/info", userInfo)
err := http.ListenAndServe("0.0.0.0:8880", nil)
if err != nil {
fmt.Println("http listen failed")
}
}
PS E:\golang\go_pro\src\safly> go run demo.go
called by template
called by template
called by template
called by template
called by template
called by template
render data: hello world<html>
<head>
<title>
</title>
</head>
<body>
<p>
hello,safly
{safly 30}
</p>
</body>
</html>